FYI, > isZero <- function(x, neps=1, eps=.Machine$double.eps, ...) { + (abs(x) < neps * eps) + }
> x <- seq(from=0, to=4, by=0.1) > isZero(x[4]-0.3) [1] TRUE > isZero(x[4]-0.3, neps=1) [1] TRUE > isZero(x[4]-0.3, neps=0.1) [1] FALSE You could also have called isZero() isValueSmallEnoughForWhatINeed(). My $.02 /Henrik On Mon, Jun 18, 2012 at 2:29 PM, Bert Gunter <gunter.ber...@gene.com> wrote: > Nope. round() is not failsafe either. Basically, there is theoretically no > way to guarantee immunity to floating point error in conditional > comparisons. You need to either switch to integers -- which **are** exactly > represented -- or figure out another way. > > Of course, practically speaking, sufficient rounding will work. It's just > that it **can** always break. ... and you know Murphy's first law. > > -- Bert > > On Mon, Jun 18, 2012 at 1:54 PM, hamoreno <hamor...@asu.edu> wrote: > >> Thanks everyone... Seems that I will have to use round before seq to make >> sure everything has the correct precision. >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/Inconsistency-using-seq-tp4633739p4633750.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.